Can confirm that there is a pretty significant difficulty ramp in the games, especially in Tropical Freeze. If you don't bother with the collectables, most of the levels are manageable but then you're losing out on most of the content. I can see the Bosses be where most people get stuck. I spent hours on the final boss of Tropical Freeze.
I wouldn't say that the difficulty is unfair but the physics take getting used to and a lot of the deaths come from not knowing what obstacle to expect which I'm personally not a fan of. That's nothing new to the overall DK series, but with these levels being much longer than the SNES, it does feel more punishing.
If you have a switch, I'd go with that version of Tropical Freeze. They added in Funky Kong as a playable character to serve as an easy mode, which seems more manageable. Sure it may not be as gratifying as master a level but at least you get to appreciate the level design and music
